# Greenhouse effect

Gases like carbon dioxide and methane trap heat in the air, keeping Earth warm enough for life.

Biology (school) · Part 08: Humans and the environment · Card 2 of 10 · Last updated 2026-10-19

## Analogy

A blanket around the planet.

## In practice

Extra carbon dioxide from burning fossil fuels makes the blanket thicker.

## Practice

### Flashcards

- **Name two greenhouse gases.** Carbon dioxide and methane.

### Interview questions

**Explain how human activities contribute to global warming.**

- Burning fossil fuels releases carbon dioxide
- Deforestation reduces carbon dioxide uptake
- Farming releases methane from cattle and rice paddies
- Greenhouse gases trap more heat, so temperatures rise

## Questions people ask

### Is the greenhouse effect bad?

The natural greenhouse effect is vital. Without it, Earth's average temperature would be about minus 18 degrees Celsius instead of roughly 15, too cold for most life. The concern is the enhanced greenhouse effect, caused by extra gases from human activity trapping additional heat.

### How do greenhouse gases trap heat?

The Sun's light passes through the air and warms the ground. The ground gives off heat as infrared radiation. Greenhouse gases absorb some of this heat and send part of it back down instead of letting it escape into space, so the lower atmosphere stays warmer.

## Related concepts

- [Global warming](https://studyvisually.com/learn/science/biology-school/biology-school-part-8/biology-school-part-8-concept-3)
- [Deforestation](https://studyvisually.com/learn/science/biology-school/biology-school-part-8/biology-school-part-8-concept-4)

Web page: https://studyvisually.com/learn/science/biology-school/biology-school-part-8/biology-school-part-8-concept-2
Study this card in the app: https://studyvisually.com/app/learn?category=biology-school&card=biology-school-part-8-concept-2